Type-3 ryanodine receptors mediate hypoxia-, but not neurotransmitter-induced calcium release and contraction in pulmonary artery smooth muscle cells.
Type-3 ryanodine receptors mediate hypoxia-, but not neurotransmitter-induced calcium release and contraction in pulmonary artery smooth muscle cells.
复制标题
3型ryanodine受体介导缺氧 - 但没有神经递质诱导的钙释放和肺动脉平滑肌细胞的收缩。
DOI：
10.1085/jgp.200409232
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发表时间：
2005-04
影响因子：
3.8
通讯作者：
Wang, Yong-Xiao
中科院分区：
文献类型：
--
作者：
Zheng, Yun-Min;Wang, Qing-Song;Rathore, Rakesh;Zhang, Wan-Hui;Mazurkiewicz, Joseph E;Sorrentino, Vincenzo;Singer, Harold A;Kotlikoff, Michael I;Wang, Yong-Xiao
在这项研究中，我们检查了 RyR 亚型的表达以及 RyR 在神经递质和缺氧诱导的肺动脉平滑肌细胞 (PASMC) 中 Ca2+ 释放和收缩中的作用。在穿孔膜片钳条件下，用咖啡因或去甲肾上腺素肌醇三磷酸受体 (IP3R) 最大程度地激活 RyR，可诱导新鲜分离的大鼠 PASMC 中 [Ca2+]i 和 Ca2+ 激活的 Cl− 电流的等效增加。在最大IP3诱导的Ca2+释放后，咖啡因和氯间甲酚均不诱导反应，而之前应用咖啡因或氯间甲酚则阻断IP3诱导的Ca2+释放。在培养的人 PASMC 中，缺乏 RyR 的功能性表达，在细胞外 Ca2+ 存在和不存在的情况下，咖啡因无法影响 ATP 诱导的 [Ca2+]i 增加。 RyR 拮抗剂钌红、兰尼定、丁卡因和丹曲林极大地抑制了新鲜分离的大鼠 PASMC 中亚最大去甲肾上腺素和缺氧诱导的 Ca2+ 释放和收缩，但不影响培养的人 PASMC 中 ATP 诱导的 Ca2+ 释放。实时定量 RT-PCR 和免疫荧光染色表明，新鲜分离的大鼠 PASMC 中所有三种 RyR 亚型（RyR1、RyR2 和 RyR3）的表达相似。在从 RyR3 敲除 (RyR3−/−) 小鼠中新鲜分离的 PASMC 中，缺氧诱导的 Ca2+ 释放和收缩显着减少，但不是次最大去甲肾上腺素诱导的。钌红和丁卡因可以进一步抑制 RyR3−/− 小鼠 PASMC 中 [Ca2+]i 的缺氧增加。总的来说，我们的数据表明（a）RyRs 在次最大去甲肾上腺素和缺氧诱导的 Ca2+ 释放和收缩中发挥重要作用； (b) 所有三种亚型 RyR 均表达； (c) RyR3 基因敲除显着抑制缺氧，但不抑制 PASMC 中次最大去甲肾上腺素诱导的 Ca2+ 和收缩反应。
In this study we examined the expression of RyR subtypes and the role of RyRs in neurotransmitter- and hypoxia-induced Ca2+ release and contraction in pulmonary artery smooth muscle cells (PASMCs). Under perforated patch clamp conditions, maximal activation of RyRs with caffeine or inositol triphosphate receptors (IP3Rs) with noradrenaline induced equivalent increases in [Ca2+]i and Ca2+-activated Cl− currents in freshly isolated rat PASMCs. Following maximal IP3-induced Ca2+ release, neither caffeine nor chloro-m-cresol induced a response, whereas prior application of caffeine or chloro-m-cresol blocked IP3-induced Ca2+ release. In cultured human PASMCs, which lack functional expression of RyRs, caffeine failed to affect ATP-induced increases in [Ca2+]i in the presence and absence of extracellular Ca2+. The RyR antagonists ruthenium red, ryanodine, tetracaine, and dantrolene greatly inhibited submaximal noradrenaline– and hypoxia-induced Ca2+ release and contraction in freshly isolated rat PASMCs, but did not affect ATP-induced Ca2+ release in cultured human PASMCs. Real-time quantitative RT-PCR and immunofluorescence staining indicated similar expression of all three RyR subtypes (RyR1, RyR2, and RyR3) in freshly isolated rat PASMCs. In freshly isolated PASMCs from RyR3 knockout (RyR3−/−) mice, hypoxia-induced, but not submaximal noradrenaline–induced, Ca2+ release and contraction were significantly reduced. Ruthenium red and tetracaine can further inhibit hypoxic increase in [Ca2+]i in RyR3−/− mouse PASMCs. Collectively, our data suggest that (a) RyRs play an important role in submaximal noradrenaline– and hypoxia-induced Ca2+ release and contraction; (b) all three subtype RyRs are expressed; and (c) RyR3 gene knockout significantly inhibits hypoxia-, but not submaximal noradrenaline–induced Ca2+ and contractile responses in PASMCs.